Since the Ultimate cart upsell application is no longer available, Could anyone recommend an application that works such as the cart drawer works on Kettle and fire.
I am not sure if they are using the Ultimate cart drawer but it seems like it. I have not seen any cart upsells applications that provide different gifts/rewards as your order value/Quantity increases along with the integration with recharge.
I'd recommend looking into the app called MonsterUpsells if you are looking for a similar interface to what you see from that store. It's not identical by any means, but they do display messaging of how much the customer is away from unlocking the next deal/upsell. Feel free to check out their app demo here.
If there is anything else I can help you with, please let me know.